Posted
by
Soulskill
on Tuesday January 22, 2013 @07:30PM
from the my-decoy-phone-will-fool-them-all dept.

jfruh writes "Call it Google Analytics for physical storefronts: if you've got a phone with wi-fi, stores can detect your MAC address and track your comings and goings, determining which aisles you go to and whether you're a repeat customer. The creator of one of the most popular tracking software packages says that the addresses are hashed and not personally identifiable, but it might make you think twice about leaving your phone on when you head to the mall."

Of course marketing guys are going to be more creative in tracking you. I automatically turn off my WiFi when I hit the road. I use a car dock with my Droid, and I use a simple app that detects when I put it in the car dock. It will turn off WiFi, and turn on Bluetooth. When I remove it from the car dock, I could either restore the previous WiFi setting, or leave it off. I generally leave it off unless I'm going somewhere I trust the WiFi, like home or the office.

Android has a nifty little program called Llama [google.com] that I use for pretty much the same thing. Get home, WiFi on, leave the house, WiFi off. The tool has other benefits too, like going into silent mode when home at night so random emails don't wake me. But thanks to Llama, I usually don't have to mess with my WiFi settings unless I'm in a strange place that I know has free WiFi and I want to leech off of it instead of my data connection.

We all know that Google's wifi geolocation stuff works this way - by tracking which fixed wifi base stations are in range and correlating with a GPS fix. People forget that Google can also identify other phones within range of your phone, and they know which Google accounts are attached to those devices.

While that is certainly a possibility, I doubt that it is currently happening because it requires putting the wifi nic into monitor mode in order to sniff for wifi packets from nodes that are not associated with the same access point or ad-hoc network. The vast majority of wifi nics can not transmit when in monitor mode - thus making it useless for normal networking, which would tend to tip people off pretty quickly that something wasn't kosher.

If you have documented evidence of google using monitor mode on people's phones, bring it on. That is the kind of thing that needs to be widely publicized if it is happening.

Turn off "location" and other "always want the network" apps that you don't need. Put your mail in "on demand" rather than "periodically polling" mode. Set your phone so the only thing it's routinely monitoring for over the air are incoming phone calls and texts.

At this point your WiFi will be a waste of battery when you aren't actually using your phone.

Actually, you don't even need to turn off wifi. Just set your phone to not automatically join any public wifi.
Wireless clients, including the phone, compiles a list of access points you can join using the ESSID broadcast from the access point. In other words, the access points just dumbly advertise their presence and don't know who are looking until your device tries to join.